In today's market there are many forms of dispenser apparatus which through a pumping mechanism communicate liquid from a reservoir in a receptacle, such as a bottle or the equivalent, to an orifice. The dispensers overall have been capable of passing liquid from the orifice in dose, spray or atomized form, the latter action, however, being limited to liquids of relatively low viscosity in the range of only a few centipoises or those liquids which contain no polymers of high molecular weight such as may be found in consumer-type household products of the cosmetic and cleaning variety.
When the liquid to be discharged from the orifice is of a higher viscosity or one which may be difficult to atomize because of the presence of high molecular weight constituents the industry has resorted to the use of propellants to achieve atomization of the liquid. The use of these propellants now is being studied in view of the possibility that their use has a detrimental effect on the environment.